The use of fuel cells in different applications, for example in a vehicle or a stationary application is thoroughly known. A fuel cell system thereby supplies electrical loads with electrical energy. To this end, the fuel cell system comprises a fuel cell, which for example is formed as a stack. The fuel cell generates an electrical voltage making use of the chemical reaction of a cathode gas and an anode gas, wherein as cathode gas oxygen-containing gases, in particular air, are usually used, while hydrogen-containing gases are employed as anode gas as a rule. In many applications, the fuel cell system is part of an arrangement, wherein the arrangement frequently comprises an electrical load system, in which different electrical loads or first loads are supplied with an electrical voltage. To this end, the load system comprises in particular a load network battery. Here, as a rule, the voltage of the load network and the electrical voltage generated by the fuel cell are at different voltage levels. In other words, this means that while a load network voltage of the load system, in particular of the load network battery, is at a load network voltage level, the cell voltage of the fuel cell has a cell voltage level that differs from the load network voltage level. The fuel cell system itself comprises a plurality of electrical loads or system loads such as for example a blower, control valves and a control unit. Since the fuel cell during a starting operation of the fuel cell system cannot provide electrical energy directly, the fuel cell system during the starting operation requires an external energy supply for supplying the system loads.
Such a fuel cell system is known for example from DE 10 2009 030 236 A1.